TDK Corp. recently introduced a new EPCOS NTC sensor element designed for measuring temperatures up to 650 °C. It is based on a high-temperature ceramic sensor element that is connected to a metallized aluminum oxide rod and then glass-encapsulated. The sensor element offers high-precision measurement with a temperature tolerance of about ±1 K at 200 °C. The component obtains its particular ruggedness from the glass encapsulation. The new sensor is available optionally with wires welded to the aluminum-oxide rod. The component is 16 mm long and the glass encapsulation has a diameter of 2 mm.
The high-temperature sensor is qualified to AEC-Q200 and designed for use in especially demanding automotive electronics applications, for example, in exhaust gas recirculation systems. These are used mainly on diesel engines to reduce excess oxygen in the combustion gas and thereby minimize the formation of nitrogen oxides at high combustion temperatures. In the recirculation systems the NTC sensors measure the temperature of the exhaust gas and thus help to protect the engine against overheating - in particular, the cylinder head and valve seats.
In e-mobility applications the new sensors are able to monitor the temperature of fuel cells that are used in electric vehicle drive systems for the direct generation of electrical energy from hydrogen. Applications can also be found in household appliances, for example in self-cleaning ovens that operate on the pyrolytic principle. These work by heating the oven interior to a temperature of about 500 °C which breaks down the long-chain molecules of the food residues and reduces them largely to gas and ash. The necessary temperature is regulated and stabilized by the NTC sensors.